example: A hockey puck of mass m moving in a circular path of radius R on a horizontal frictionless surface.

For an object of mass m to move
in a circle of radius R with a constant speed v, there must be a net centripetal force (mass × centripetal acceleration) with the magnitude m
v2/R and
directed along the radius toward the centre of the circle. In the example above the tension T
provide the centripetal force necessary to keep the object in circular motion.